Target Options for a Data Capture Device with Intuitive Aiming Involving Specular Objects

ABSTRACT

A presentation scanner allows an operator to easily place an object being scanned within the scanner&#39;s field of view in order to enhance usability of the scanner. A partially transmitting and partially reflecting surface, like a mirror, is used. An aiming pattern or target indicator is projected from an aiming source to the surface. The aiming pattern or target indicator is seen by an operator who aligns the object, which is reflected from the surface back to the operator, to be placed over or within the aiming pattern that appears at the surface. Once aligned, a camera captures the image of the optical code.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C § 119(e) of U.S.Application No. 62/438,511 filed Dec. 23, 2016, which claims priorityunder 35 U.S.C. § 120 of U.S. application Ser. No. 15/480,124 filed Apr.5, 2017, all of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The current state of the art of fixed-position (non-handheld) opticalcode scanners do not rely on aiming devices to assist the operator inplacing the optical code in the correct reading position. Such scannerstypically require the operator to face the optical code towards thescanner and away from the operator's field of vision. Thus, an aimingbeam or other targeting method, such as those used on handheld scanners,is ineffective because the operator cannot see the aiming beam or othertargeting method on the optical code.

Some scanners use an aiming or “pointer” beam, which is projected ontothe surface of the object being scanned. The image of this beam on theobject is viewed by the operator as a reflection in the scanner'smirror. If the object being scanned has an optically diffusive surface,then the pointer beam is easily seen on the object. However, if theobject being scanned is highly specular or shiny, such as a cell phone'sdisplay surface, then the pointer beam is very difficult to see.

SUMMARY

Embodiments of the invention are defined by the claims below, not thissummary. A high-level overview of various aspects of embodiments of theinvention is provided here for that reason, to provide an overview ofthe disclosure and to introduce a selection of concepts that are furtherdescribed below in the detailed description section. This summary is notintended to identify key features or essential features of the claimedsubject matter, nor is it intended to be used as an aid in isolation todetermine the scope of the claimed subject matter.

The present invention does not rely on the aiming device's image (i.e.pointer beam) reflecting off the object, but rather visuallysuperimposes a directly-viewed target pattern with a reflected image ofthe entire object as seen in the mirror or surface.

A fixed position scanner may be created, which allows the operator toview an aiming beam or target on the optical code. As such, visualtargets can be created to use with “virtual aiming” scanners.Embodiments of the present invention create a targeting or aimingpattern, in one of several different ways, that is visually superimposedover a virtual image of the optical code by use of a partiallytransmissive mirror. The pattern allows an operator of a scanner toeasily align the optical code with the scanner's field of view, whichfacilitates reading the optical code.

Embodiments of the present invention allow the operator to see theoptical code on an object by viewing a reflection in a mirror. Insteadof having a pointer beam reflecting from the object and also visible ina mirror, an aiming device is used, which is an illuminated targetindicator, reticle, or pattern, which is placed behind a negative powersemi-reflective surface near the position of a virtual image of theobject with the optical code. Because the targeting indicator is vieweddirectly through the partially transmissive mirror, rather than afterbeing reflected from the object, the difficulty in viewing a pointer oraiming beam on specular surfaces is eliminated.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Illustrative embodiments of the present invention are described indetail below with reference to the included drawing figures, wherein:

FIG. 1 is an exemplary graphic target with etched arrows and rectangularitem, implemented in accordance with an embodiment of the presentinvention;

FIG. 2 is an exemplary scanning system with a set of LEDs, implementedin accordance with an embodiment of the present invention;

FIG. 3 is an exemplary scanning system with a graphic target,implemented in accordance with an embodiment of the present invention;

FIG. 4 is another exemplary scanning system with a graphic target,implemented in accordance with an embodiment of the present invention;

FIG. 5 is an exemplary scanning system with a plate, implemented inaccordance with an embodiment of the present invention

FIG. 6 is a diagram of virtual image formation in accordance with anembodiment of the present invention;

FIG. 7 is an implementation of FIG. 2 depicting the scanning of a cellphone display;

FIG. 8 is an exemplary scanning camera with a set of LEDs as targetindicators, implemented in accordance with an embodiment of the presentinvention;

FIG. 9 is another exemplary scanning system with a set of LEDs depictingthe physical relationship between the elements, implemented inaccordance with an embodiment of the present invention;

FIG. 10 is an image of a cell phone display positioned at a height of 42inches from the ground and located 2.5 inches from a reflecting object,with an observer seeing the reflecting object at an eye height of 48inches from the ground;

FIG. 11 is an image of a cell phone display positioned at a height of 42inches from the ground and located 2.5 inches from a reflecting object,with an observer seeing the reflecting object at an eye height of 60inches from the ground;

FIG. 12 is an image of a cell phone display positioned at a height of 42inches from the ground and located 2.5 inches from a reflecting object,with an observer seeing the reflecting object at an eye height of 72inches from the ground; and

FIG. 13 is an exemplary scanning device illustrating a surface with atransmissive feature showing the boundary line and arrows and areflective feature showing the reflection of the identification card,implemented in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

Embodiments of the present invention relate generally to an imagingscanner that has enhanced usability and aiming to aid an operator.Accordingly, the present invention implements a mirror to aid theoperator in seeing hidden optical codes or bar codes during scanning.The mirror can incorporate see-through capability to allow a person toscan items. Further, the present invention implements an aiming patternor aiming frame to function as a field of view for a scanning camera.The aiming pattern or aiming frame allows the operator to scan opticalcodes or bar codes, which appear as virtual images on the mirror.

In a first aspect, a data capture system with virtual aiming is providedthat includes a scanning camera positioned to receive an image of afirst item's data through a mirror having both transmissive andreflective properties. The mirror is positioned between the scanningcamera and the first item. The first item's data partially shares afield of view with an operator's visual field of the mirror. Theoperator sees a reflection in the mirror of the image of the firstitem's data positioned by the operator on a first side of the mirror. Anaiming pattern is transmitted towards a second side of the mirror suchthat that the aiming pattern appears on the first side of the mirror dueto the transmissive properties of the mirror. The mirror is located sothat the operator can aim the first item's data at the aiming pattern.The operator has a first line of sight to the first item's data from thereflection in the mirror. The operator aligns the first item's data withthe aiming pattern on the first side of the mirror so that the scanningcamera has a second line of sight to the first item's data. The scanningcamera captures an image of the first item's data.

In another aspect, an imaging scanner with enhanced usability and aimingis provided that includes a scanning camera positioned to receive animage of a first item transmitted through a mirror. The mirror has apartially reflecting and partially transmitting coating. The scanningcamera sees the image of the first item through the mirror where thefirst item is positioned by an operator on a first side of the mirrorand the scanning camera is on a second side of the mirror. The mirror islocated so that the operator can position the first item's data and theoperator can aim the first item's data at the scanning camera. Theoperator has a first line of sight to the first item's data through areflection on the first side of the mirror and the scanning camera has asecond line of sight to the first item's data from the second side ofthe mirror. The mirror is also located so that the operator positionsthe first item's data such that the scanning camera sees the firstitem's data through the mirror.

In yet another aspect, an imaging scanner with enhanced usability andaiming is provided that includes a scanner window formed in a sphericalshape and coated with a partially reflective layer. The scanner windowforms a virtual image of an optical code that is located a distance fromthe imaging scanner. An aiming frame, which is illuminated andoriginates from an aiming source, shows a field of view of a scanningcamera on the scanner window. The scanning camera captures the virtualimage of the optical code when the optical code is positioned so thatthe virtual image of the optical code is placed in or over the aimingframe at the scanner window.

Implementations of an embodiment of the present invention include anenhanced aiming mirrored scanner that uses a convex (negative opticalpower) partially reflective mirror for an operator to view a reflectionof an object. The fairly strong negative power of the optic and itsclose relative position to the object being viewed allows the mirror tooperate as a field optic, greatly increasing the field of view overwhich the object being scanned can be seen. The scanning camera isplaced behind the partially transmissive mirror and views the objectthrough this surface. In the context here, a transmissive mirror is onewhere something, such as light, can be seen through the mirror.Additionally, a partially transmissive mirror is one where something canbe seen through the mirror as well as can be reflected in the mirror.

In implementations of embodiments of the present invention, the mirroris formed as a convex thin shell, which may have a surface figure whichis spherical or aspherical in nature. Because the mirror is a thin shellwith essentially locally parallel surfaces, a camera may view the objectthrough this surface with very little induced aberrations.

A targeting indicator is typically an illuminated pattern, which isplaced approximately where the virtual image of the object being scannedis focused. Sometimes, the targeting indicator is referred to as anaiming pattern or aiming frame. The target pattern is viewed through thepartially transmissive surface and is seen by the operator as beingsuperimposed on the virtual reflected image of the object being scanned.The operator may align the object's optical code to the target indicatorin order to ensure that the optical code is centered to the scanningcamera's field of view. In other embodiments, the targeting indicatorcan be an unilluminated pattern drawn on or near a surface, such as amirror.

Targeting indicators can include a pattern of light emitting diodes(LEDs) arranged in a way to enhance aiming. Other targeting indicatorscan include patterns such as a rectangle, a circle, nested rectangles,concentric circles like ‘bulls-eye’, crosshairs, an ‘X’, arrows,spirals, and asterisks, to name a few. Other patterns may becontemplated, which are not mentioned here. Enhancements may be made tothe targeting indicator such that it changes character upon a successfuldecoding of data on the presented object. This may include changing thecolor of the targeting indicator, its brightness, or rate of duty cycleof flashing.

In an implementation of an embodiment of the present invention, thetargeting indicator is normally flashing one color on and off, forexample blue, at a moderate rate, such as one Hertz, in order to callmore attention to proper aiming of the object to be read. When asuccessful read occurs, the indicator may switch to a green color, forinstance, and hold this state continuously on for a longer period, say1.5 seconds, and then return to the targeting mode of a blue one Hertzflashing condition.

In FIG. 1, a graphic target 100 is shown that is used to provide atarget indicator when illuminated. Graphic target 100 may be an opaquetarget where bright areas are a light reflective color, which is suitedfor front illumination. Alternatively, the bright areas may be madetransparent or translucent, or maybe used with back illumination. Frontillumination means that some type of light shines on the front surfaceof graphic target 100. Back illumination means that some type of lightshines on the back surface of graphic target 100. With graphic target100, the bright areas include arrows 110 and rectangular pattern 120. Asone of ordinary skill in the art understands, the bright areas may bemade of different designs and shapes.

Turning to FIG. 2, an exemplary scanning system 200 is shown with amirror 205, which is partially transmissive and partially reflective, acamera 210, and an arrangement of LEDs 215. Mirror 205 is located infront of camera 210 and LEDs 215. Camera 210 can capture an image of anobject that appears on the left side of mirror 205. As shown, all thecomponents of system 200 are shown to the right side of mirror 205.Because of the transmissive nature of mirror 205, camera 210 capturesthe image in its field of view. LEDs 215 project an aiming patternthrough mirror 205, which can be seen through mirror 205 due to thetransmissive and reflective properties of mirror 205. Camera 210 andLEDs 215 can be connected together, located together but not connected,or located in proximity to each other. This proximity is dependent onand limited to the size of the housing that contains scanning system200.

Camera 210 can be a solid state camera or another type of camera thatcan capture images. More particularly, camera 210 is also referred to asa scanning camera. Camera 210 can scan or read optical codes, bar codes,or other data that are located on items or packages placed within thescan zone at scanning system 200.

The location and angle of camera 210 are fixed relative to mirror 205.This means that as mirror 205 is moved or adjusted, camera 210 maintainsthe same relative position to mirror 205.

An alternative embodiment to the arrangement of LEDs 215 is to use asimple illuminated target graphic, which is front- or back-illuminated.This graphic may be a simple printed pattern, similar to the onedescribed in FIG. 1, or it may contain another kind of printablegraphics and/or characters. These graphics and/or characters mayinclude, but are not limited to, a rectangle, a circle, nestedrectangles, concentric circles (i.e. ‘bulls eye’), crosshairs, an ‘X’,arrows, spirals, and asterisks, to name a few. Simple instructions maybe printed as well. In addition, various colors may be used for addedemphasis. Also, various colors of the illumination may be sequenced onand off so that the colors of the graphic become visible or not, thus,adding more flexibility to the display of information for targeting orother purposes.

In FIG. 3, an exemplary scanning system 300 is shown with mirror 205,camera 210, a graphic target 330, and LEDs 325. Mirror 205 is located infront of camera 210, LEDs 325, and graphic target 330. Camera 210captures an image of an object that appears on the left side of mirror205. As shown, all the components of system 300 are shown to the rightside of mirror 205. Because of the transmissive nature of mirror 205,camera 210 captures the image in its field of view. LEDs 325 project afront illumination onto graphic target 330 causing the aiming pattern oraiming frame from graphic target 330 to be visible through mirror 205.The aiming pattern or aiming frame can be seen through the mirror 205 asdiscussed above. Graphic target 330 is similar to graphic target 100discussed in FIG. 1. Camera 210 and graphic target 330 can be connectedtogether, located together but not connected, or located in proximity toeach other. Similarly, as discussed above, the proximity is dependent onand limited to the size of the housing that contains scanning system300.

Continuing with FIG. 4, an exemplary scanning system 400 is shown withmirror 205, camera 210, a translucent target 435, and LEDs 440. Mirror205 is located in front of camera 210, translucent target 435, and LEDs440. Camera 210 captures an image of an object that appears on the leftside of mirror 205. As shown, all the components of system 400 are shownto the right side of mirror 205. Because of the transmissive nature ofmirror 205, camera 210 captures the image in its field of view. LEDs 440project a back illumination onto translucent target 435 causing anaiming pattern or aiming frame to be projected from translucent target435 through mirror 205. The aiming pattern or aiming frame can be seenthrough mirror 205 as discussed above. Translucent target 435 is similarto graphic target 100 discussed in FIG. 1. Camera 210 and translucenttarget 440 can be connected together, located together but notconnected, or located in proximity to each other.

Another alternative embodiment to LEDs 215, graphic target 330, andtranslucent target 435 for creating an aiming pattern or aiming frame isan edge illuminated transparent plate with a design etched into theplate's surface. This technique is based on the principle of frustratedtotal internal reflection, whereby light launched into the edge of theplate will propagate through the plate and ‘leak out’ wherever thesurface is etched. The edge illumination may be monochromatic, or may beof multiple colors. The colors may be sequenced for additionalattention-getting. Multiple plates with different patterns may bestacked so that patterns may be alternately selected in time. Thesequencing of multiple plates may also give a three-dimensionalsequencing effect because of the different distances of each from theoperator.

In FIG. 5, an exemplary scanning system 500 is shown with mirror 205,camera 210, a transparent or semi-transparent plate 550, a targetingpattern 560, and LEDs 555. Mirror 205 is located in front of camera 210,plate 550, LEDs 555, and targeting pattern 560. Camera 210 captures animage that appears on the left side of mirror 205. As shown, all thecomponents of system 500 are shown to the right side of mirror 205.Because of the transmissive nature of mirror 205, camera 210 capturesthe image in its field of view. LEDs 555 illuminates the edges of plate550 causing target pattern 560 to be visible through mirror 205. Targetpattern 560 can be seen through mirror 205 as discussed above. Camera210 and plate 550 can be connected together, located together but notconnected, or located in proximity to each other.

In various embodiments discussed above, geometrical shapes, text, or acombination of both can be implemented to clearly define the target scanzone at mirror 205 for camera 210 and an operator, where camera 205 andthe operator are located on opposite sides of mirror 205. Additionally,mirror 205 can be flat or concave. Mirror 205 can be a lens or surfacethat has been coated to provide reflective properties but also retainthe transmissive properties. In other embodiments, mirror 205 can befully reflecting, but also contain an aperture for camera 210 to view anobject through the aperture put in mirror 205.

In FIG. 6, a virtual image formation concept 600 is shown with a convexreflective surface 610. Surface 610 has a radius r and is coated with anoptically reflective material. This “optic” has a focal point f, whichis at a distance r/2 from the center of the circle or spherical shapefor surface 610. The object obj, when viewed by an operator at eye, byway of the reflection from surface 610, appears as a virtual image atvi.

Turning now to FIG. 7, scanning system 200 is shown in a position toscan a cell phone display object 710 of a cell phone 720 in anillustration 700. Object 710 is viewed through mirror 205, which is apartially transmitting and partially reflecting optical element, bycamera 210.

In FIG. 8, an illustration 800 shows internal components of scanningsystem 200. Scanning camera 210 has a circuit board 840 and a lens andimager assembly 820. Additionally, LEDs 215, which are used as a targetindicator, are shown connected to scanning camera 210.

FIG. 9 demonstrates the nature of the partially transmitting andpartially reflecting optical surface (i.e. mirror 205) and itsrelationship to scanning camera 210. The targeting indicator is placedroughly in the vicinity of the virtual image, which occurs on theconcave side of the surface.

FIGS. 10 through 12 are simulation images of what observers of variousheights would see with a cell phone held at the same desired locationfor all. In the example here, the cell phone 720 is located 42 inchesabove the floor and is located 2.5 inches asway from the reflectingoptic. FIG. 10 shows what a person with an eye height of 48 inches wouldsee. FIG. 11 shows what a person of an eye height of 60 inches wouldsee. FIG. 12 is the result for a person with an eye height of 72 inches.Notice that over an eye height range of 30 inches, the offset errorbetween the display virtual image center and the targeting indicator isvery small, which shows the robust nature of the invention.

From the descriptions above, the core idea is to use the scanner windowitself, preferably formed in a spherical or convex shape, and coatedwith a partially reflective layer, to form a virtual image that can beseen by the user, without changing the scanner's shape and basiccomponents. An aiming frame illuminated either by a slab type LEDillumination or a back/front illuminator shows the user the usable fieldof view of the camera. In some cases, the back illuminator is switchedoff during camera acquisition.

A reduction in transmitted power caused by having a partially reflectivewindow is not considered an issue and can be compensated by a flashilluminator placed behind the window. When a cell phone or other deviceis presented, no illumination is needed because of the amount ofillumination at the cell phone display.

Turning to FIG. 13, an illustration 1300 shows a scanning device 1310scanning data from an identification card 1350. Scanning device 1310includes a surface 1320 (which is similar to mirror 205). Surface 1320has a transmissive feature that allows a targeting indicator 1330originating from a targeting source inside of scanning device 1310 to bevisible to a user as a rectangular boundary line and arrows.Additionally, surface 1320 has a reflective feature that shows areflection 1340 of the data on the back of identification card 1350.

Although not shown, scanning camera 210 is located inside scanningdevice 1310. One embodiment can be established where scanning camera 210sees and captures the data on the back of identification card 1350 byseeing through surface 1320 due to surface 1320's transmissive feature.Another embodiment can be established where scanning camera 210 sees andcaptures the data on the back of identification card 1350 by seeingthrough an aperture made through surface 1310. In this case, scanningcamera 210 does not depend on the transmissive feature of surface 1310to see the data on the back of identification card 1350. In eitherembodiment, scanning camera 210 and the targeting indicator have thesame or similar lines of sight.

In another embodiment, the back illuminated aiming pattern 1330indicates to the user the extension of scanning camera 210's field ofview. The partially reflecting surface 1320 shows the user code 1340 asa reflection. So, proper distance can be selected in order to frame thewhole code 1340 inside pattern 1330. Aiming pattern 1330 is generated bythe various types discussed above.

Continuing with FIG. 13, the coating on surface 1320 can be done on theinterior (concave) side of surface 1320 to protect it from wear. As anadvantage, in scanner 1310 with a small window such as surface 1320(i.e. reflective curved window), one can understand how far away a labelmust be in order to be completely in camera's 210 field of view. Ratherthan center aiming, this feature provides advantages to compactpresentation scanners.

One method can be to have the shortest dimension of the field of view atnear field be somewhat larger than the longest dimension of the largestdesired label. Once this is determined, the dimension at the near fielddistance is transferred to the virtual image at surface 1320, where itwill be smaller by the magnification factor. If the illuminated target(i.e. back of identification card 1350) is at the virtual image, thenthe smaller dimension of the target should match the virtual imagedimension. Camera 210's lens can be calculated to match the field ofview at near field distance, and placed accordingly. At some distance,the targeting indicator and the object line up.

As an example, the cell phone captures indicated by FIGS. 10-12 are usedat 5.4 millisecond exposure pulse, as measured on the aimer LED currentsense resistor. There is no illumination LED on through one of the 100millimeter coated mirrors, which is approximately a 7 millimetereffective focal length (EFL) lens wide open, which is about an f/2.5 tof/3.

In using a prototype with the SixKi decoding application, the scannerseems quite usable as a presentation-mode device with current 5.4millisecond exposure, no illumination, f2.8 or so. Because thesesettings give a decent image in typical office ambient for a typicallabel, they also work quite well for label images on the cell phonewithout changing anything. The simplifying principle is the fact thatthis is presentation-mode only, where there is no sweeping. Because ofthe box-style virtual aiming target that appears on the mirror orsurface, one tends to not sweep while attempting to place the labelwithin the box. Another helpful fact is that despite the narrow depth offield due to the low f-number, one can fairly easily see when thevirtual image of the label is in the plane of the target, which is “nearbest focus.” It is very easy to bring the label in, line it ups with thebox, and position it at the right distance for reading. Some ambientlight may be reflected onto the label as the label gets close to themirror. If no illumination is required, there may not be a need for aspecial cell phone mode.

In another embodiment, a set of barcode illuminator LEDs can be placedexternal to the mirror or surface, facing towards a potentialnon-illuminated display barcode (i.e. label). The LEDs could be hiddenfrom a user's or operator's eyes, but would illuminate the field at somerate. The idea would be to switch between a short exposure with theseilluminators on for paper-type labels, and a longer non-illuminatedexposure when looking for self-illuminated displays such as a cellphone. The ratio of frames of these two modes could be adjusted to matchthe expected mix of types depending upon the application. In both modes,the internal target graphic illuminators would be turned off duringcamera exposures.

As discussed above, implementations of embodiments of the presentinvention enhance the user of fixed-type scanning devices by allowingvisual operator feedback in the form of views of normally hiddensurfaces of items being scanned. These views may be shown on a mirror orspecular surface. The goal is to provide as much ease to the operator toaim optical codes or bar codes at a scanner. The scanning camera's fieldof view is shown as a target on the surface. As the operator lines upthe reflected object with the target on the surface, the operator knowsthe object will be in the field of view of the camera. Thus, the cameracan automatically capture the image of the object as it detects theobject has been placed in its field of view by way of the alignment withthe target on the surface.

Many different arrangements of the various components depicted, as wellas components not shown, are possible without departing from the spiritand scope of embodiments of the present invention. Embodiments of thepresent invention have been described with the intent to be illustrativerather than restrictive. Certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations and are contemplated to be within the scope of theclaims.

The invention claimed is:
 1. An imaging scanner with enhanced usabilityand aiming, comprising: a scanning camera positioned to receive an imageof a first item transmitted through a mirror, wherein the mirror has apartially reflecting and partially transmitting coating; the scanningcamera sees the image of the first item through the mirror where thefirst item is positioned by an operator on a first side of the mirrorand the scanning camera is on a second side of the mirror; the mirrorlocated so that the operator can position the first item's data and canaim the first item's data at the scanning camera, wherein the operatorhas a first line of sight to the first item's data through a reflectionon the first side of the mirror and the scanning camera has a secondline of sight to the first item's data from the second side of themirror; and the mirror also located so that the operator positions thefirst item's data such that the scanning camera sees the first item'sdata through the mirror.
 2. The imaging scanner of claim 1, furthercomprising an aiming frame that originates from an aiming source that islocated in proximity to the scanning camera, the aiming frame is visiblewhen viewed from the first side of the mirror, wherein the aiming framerepresents a field of view of the scanning camera.
 3. The imagingscanner of claim 2, wherein the operator sees the aiming frame at thefirst side of the mirror, and wherein the operator adjusts a position ofthe first item to place the reflection of the first item's data in theaiming frame at the first side of the mirror.
 4. The imaging scanner ofclaim 3, wherein the aiming frame is coaxial with an optical axis of thescanning camera.
 5. The imaging scanner of claim 4, wherein the mirrorhas a reflective coating on the second side.
 6. The imaging scanner ofclaim 4, wherein the first line of sight of the operator is not coaxialwith the second line of sight of the scanning camera.